[Slade901]

I think the problem is the Ignition Coil Housing.

One way to find out would be remove the four spark plug boots and use a known good spark plug wire in place of the spark plug boots. This way, you can test for sparks on each end of the spark plug wires. (Note: The Ignition System metal cover and the Ignition Coil Housing must be secured with a rope dangling).

This is how I tested our vehicle for ignition problem and confirmed that only two were firing and the culprit was the Ignition Coil Housing. Again, I have to lift the Ignition System Cover/Igniton Coil Housing and secure it with a rope and then remove the spark plug boot and put a known good spark plug wires in place of the spark plug boot. I use an adjustable gap spark tester to check for sparks.